A KILLER who used the so-called "gay panic" defence after bashing a man to death in a Maryborough churchyard has walked free from prison, just four years into a nine-year sentence.

Jason Andrew Pearce was charged with the murder of Wayne Robert Ruks at St Mary's Catholic Church in July 2008, but was convicted of manslaughter after using the controversial defence.

Pearce was sentenced in 2010 to nine years imprisonment, while his co-accused Richard John Meerdink received 10 years.

On July 9, Pearce was granted parole and released from jail.

Meerdink will be eligible for parole in 2016.

The mother of their victim, Joyce Kujala, has slammed the sentences, saying if her son's killers had not been able to use the "gay panic" defence, Pearce would still be in prison.

"He took my son's life and gave me a life sentence - he got four years and he's free," she said.

The devastated Sunshine Coast woman has fought hard in the years since the trial to have the men's sentences extended, and has written letters to the Director of Public Prosecutions over the case.

"My son was not gay, and that was the hardest part. It shows the defence can be used against anyone," Ms Kujala said.

"Even the CCTV footage showed no sign of a homosexual advance. It was just used as an excuse."

Under Queensland legislation, the claim of "non-violent homosexual advance" can be used as a defence in murder or assault court cases - potentially reducing a conviction from murder to manslaughter, if an accused person said their victim's behaviour provoked them into attacking.

Maryborough priest Paul Kelly, who was one of the first on the scene when Mr Ruks died, was so affected by the man's death that he launched an online petition to remove the defence, that has since gathered signatures from all over the world.

In January this year, in what was hailed as "a victory for common sense", the former state government decided the Criminal Code would be altered to ensure that unwanted sexual advances could not be used to claim provocation, unless in exceptional circumstances.

Following the election, new Attorney-General Jarrod Bleijie said he had requested a brief from the department on the issue and would consider the recommendations made by the former Labor government.

But the Attorney-General announced this week that he would not be making the planned changes to the code, and the defence would still be available in violent crimes.

Fr Kelly and Ms Kujala have criticised the decision, saying it was out of touch with the community's expectations.

"This is not a matter of gay rights, it's a matter of human rights," Ms Kujala said.

"Nobody, gay or not, should be attacked even if they did make a proposition. A lot of other people will die because of this defence. If the petition goes through to get the law amended, it can save lives."

More than 180,000 people have signed the petition to have the law repealed, at change.org/gaypanic.